Fine grind hammer mill with adjustable hammer rotor



A mril 23, 1968 R. w. STEPANEK FINE GRIND HAMMER MILL WITH ADJUSTABLE HAMMER ROTOR 2 Sheets-Sheet 1 Filed Oct. 23, 1965 INVENTOR.

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April 23, 1958 R. w. STEPANEK 3,379,383

FINE GRIND HAMMER MILL WITH ADJUSTABLE HAMMER ROTOR Filed Oct. 23, 1965 2 Sheets-Sheet 2 illlllllllll'l INVENTOR. Ro W. Skepanek United States Patent 3,379,383 FINE GRIND HAMMER MILL WITH ADJUSTABLE HAMMER ROTUR Roy W. Stepanelr, Cedar Rapids, Iowa, assiguor to Pettiboue Mulliken Corporation, a corporation of Delaware Filed Oct. 23, 1965, Ser. No. 504,253 3 Claims. (Cl. 241-86) ABSTRACT OF THE DISCLOSURE The hammer rotor or the hammer mill is adjustable with respect to the grating past which the hammers rotate. Lateral adjustable is accomplished by adjustable screws at opposite ends of a bearing block for moving it along a plate, and the plate is hinged at one end and moved vertically at its other end, which is in the direction of rotation from the hinged end, by a jack screw, the parts being firmly clamped during operation.

The invention of which the present disclosure is offered for public dissemination in the event that adequate patent protection can be given relates to hammer mills, and especially to hammer mills adapted to accomplish fine grinding.

Hammer mills used for fine grinding have presented somewhat of a problem in maintaining the close clearances between the rotating hammers and the stationary parts which are required for fine grinding. The normal procedure heretofore has been to compensate frequently for wear by adding weld metal to the hammers to build them up where they have worn. According to the present invention, the hammer mill shaft is made adjustable with respect to the stationary structure, and a sufiiciently dependable and precise adjustment device has been worked out so that it becomes practicable to maintain the desired clearances by adjusting the position of the hammer rotor.

Screw adjustments can be made in any radial direction from the rotor axis. Easily changed shims are provided in the downward direction to prevent any damage in the event a screw adjustment should loosen.

Additionally objects and advantages of the invention will be apparent from the following description and from the drawings.

Designation of figures FIGURE 1 is a cross-sectional view through a hammer mill exemplary of those with which the present invention may be used, and showing an embodiment of the preferred adjustment device, beyond the wall in the figure, in broken lines.

FIGURE 2 is a side elevation of the preferred form of adjustment device according to the present invention.

FIGURE 3 is a fragmentary vertical sectional view approximately on a vertical axial plane of FIG. 2.

Although the foregoing disclosure offered for pubic dissemination is detailed to ensure adequacy and so aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein, no matter how others may later disguise it by variations in form or additions or further improvements. The following claims are intended as the chief aim toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

Background description Except for the mounting of the shaft 11, the hammer mill of FIG. 1 may be any conventional hammer mill although the present invention is especially suitable for "ice one having narrow clearances between the rotating hammers 12 and the grate 13. Such narrow clearance are necessary for producing the fine grinding that is sometimes desired. For example, some present specifications for agricultural lime require that percent of the material pass an 8 mesh sieve and 40 percent pass a 60 mesh sieve. Not only are small clearance required but also high speeds. Heretofore, the practice has been to maintain the narrow clearances by building up worn areas frequently with welding.

In such hammer mills, limestone (or other materials to be ground) which has previously been crushed and screened to moderate size is fed down a feed chute 14 where it is shattered by impact with hammers 12, preferably rotating in the counterclockwise direction as seen in FIG. 1. This does most of the crushing by impact with minimum abrasion. The shattered pieces are thrown against the various impact bears 16 where they may be further broken. Final reduction is achieved, however, between the hammers 12 and the grate 13. In a machine of this type, the grate commonly occupies the lower half of the area immediately surrounding the hammer circle, the hammer circle being the outermost path described by the hammers.

The articles slightly larger than the size appropriate for interaction between the hammers and the grate 13 may be reduced on a preliminary breaker bar 16 which is commonly made adjustable with respect to the hammer circle.

Shaft adjustment facilities According to the present invention, the shaft 11 may be adjusted in a lateral direction with precision, and may also be adjusted vertically, even though being held in safe sturdiness in any adjusted position.

Perhaps the most commonly made adjustment will be the vertical adjustment. According to the present invention, this is made with the aid of jack screw 17. Jack screw 17 passes through lug 18 extending out from a rock plate 19 which supports bearing block 36. Conveniently bolt '17 may be threaded to a nut 20 welded to the bottom side of lug 18. The rocker plate 19 is pivoted to spaced pedestals 21 as by a hinge bolt 22. To change the height of shaft 11, jack bolt 17 is first turned to raise rocker plate 19 off of a shim assembly including cap 23 and shims 24. After removing retaining screw 26, shims are removed or replaced to provide the new height desired. Jack screw 17 is then turned to lower rock plate 19 onto cap 23. Thereafter, rock plate 19- Will be clamped firmly in place by tightening nuts 27 on bolts 28, and tightening lock nuts 27. Of course, before each new adjustment, nuts 27 and 27' will be loosened before turning jack screw 17. All of the foregoing is supported by ledge 39 which is firmly supported by brackets 29. Cap 23 is preferably provided with a cylindrical surface to fit a correspondingly shaped groove in the bottom of rock plate 19, to support the rock plate 19 firmly at the varying angles within its range of adjustment. As seen in FIG. 3, retaining screw 26 may pass through cap 23, shims 24 and screw into lug 33 extending outwardly from ledge 30.

Lateral adjustment Lateral adjustment of shaft 11 may be made by shifting bearing block 36 along rocker plate 19. This can be accomplished with precision by first loosening clampdown nuts 37 and then turning both adjustment screws 38 in the same direction to shift them both to the right or to the left, first backing off the one which would block the desired movement of block 36. Each of the bolts 38 may conveniently be threaded to a nut 39 welded to a lug 41 upstanding from rocker plate 19. When both of these adjustment screws 38 are tightened against block 36 in its desired new position, locl; nuts 42 will be tightened. Thereupon clamping nuts 37' will also be tightened and there are lock nuts 43.

Bearing block 36 is confined to lateral movement on rock plate .19 by keyway strips 44 welded to rock plate 19. These keyway strips 44 may be Welded after hearing block 36 has been suitably positioned in the course of manufacturing assembly.

It is apparent that adjustments can be made precisely easily and with dependability of maintaining the adjustment. Hence, it becomes practical to greatly prolong the running time between shut-downs for welding or replacing hammers.

I claim:

1. A fine-grind hammer mill including a hammer rotor having hammers thereon, a grating disposed arcuately closely to the hammer circle, a shaft for rotatably supporting and driving the hammer rotor, and means for adjustahly positioning the shaft including a bearing block for the shaft, a vertically movable plate supporting the bearing .block for lateral movement thereon, and means for vertically adjusting the vertically movable plate;

said means for vertically adjusting the plate including a hinge for the plate at one end, a jack screw at the opposite end and variable shim means beneath the plate, and

means for laterally adjusting the bearing block on the vertically adjustable plate comprising a guideway confining the bearing block to lateral movement, and adjustment screws bearing on opposite ends of the bearing block for sliding it one way or the other and for locking it in the position to which it is adjusted, and clamping screw means for holding the bearing block firmly in the adjusted position,

an additional clamping means for clamping the vertical adjustable plate firmly in its adjusted position hearing on said hinge and shim means.

2. A fine-grind hammer mill including a hammer rotor having hammers thereon, a grating disposed arcuately closely to the hammer circle, a shaft for rotatably supporting and driving the hammer rotor, and means for adjustably positioning the shaft including a bearing block for the shaft, a vertically movable plate supporting the hearing block for lateral movement thereon, and means for vertically adjusting the vertically movable plate;

said means for vertically adjusting the plate including a hinge for the plate at one end, a jack screw at the opposite end and variable shim means beneath the plate,

means for locking the bearing block laterally on the plate, and

clamp-down means for clamping the plate firmly down on the shim means.

3. A fine-grind hammer mill including a hammer rotor having hammers thereon, a grating disposed arcuately closely to the hammer circle, a shaft for rotatably supporting and driving the hammer rotor, and means for adjust-ably positioning the shaft including a bearing block for the shaft, a vertically movable plate supporting the bearing block for lateral movement thereon, and means for vertically adjusting the vertically movable plate;

said means for vertically adjusting the plate including a hinge for the plate at one end, a jack screw at the opposite end and variable shim means beneath the plate,

means for locking the bearing block laterally on the plate, and

clamp-down means for clamping the plate firmly down on the shim means;

said plate being disposed to extend generally in the direction of rotation from its hinge end to its jack screw end.

References Cited UNITED STATES PATENTS 748,636 12/1903 Schoellhorn et al. 241--88 1,049,412 1/1913 Sheehan. 2,420,966 5/1947 Molz et al. 241--89X AN-DREW R. IUHASZ, Primary Examiner. 

